Like the title says, what affect does the operating temperature have on the noise(s) that the primary chaincase make?? I always figured that as things heat up, the chain expands and therefore may create a little noise because of the excess slack in the chain.

But I'm experiencing just the opposite. My primary is making a slapping sound only when it is NOT up to operating temperature. Once it gets warmed up from riding, the noise goes away... But before that, it sounds like it slaps, only when under load.

But I just can't understand how heat would make the noise go away.

On a side note, I am positive that my compensating sprocket bolt is not loose, like many of the older nuts were. So that's not it. Also, my chain tensioner is fine too; I've double-checked it.

 

Interesting statements.

I feel my 09 is "motor" quieter in cooler temps.
But I don't think my ears are HD trained enough to tell much on the primary noise.

If your tensioner is working, that chain should be pretty darn snug.

 

I'm pretty sure the primary case expands (gets longer) faster than the chain , so the tension gets tighter as the primary warms up.
The auto tensioner should make up for it , but it gets tighter by little notches as it needs to.
Mine does this also.
I keep an eye on the compensator now as it did loosen up once on me.
Mick

 

You got it all backwards. the pulleys and engine grow more then the chain. The chain will always get tighter when hot.

 

Operating temp of above 350 degrees will produce a profound silence from the primary (and everywhere else).

 

My seems to have a "howl" when it gets hot. I took off the cover tonight and cold, I have about 1/4" deflection, which I think is too tight. I think I need to loosen mine up as I think it is getting tighter when it gets hotter, but what do I know?

 

Mine has a "howl" or a "whine" hot or cold. I had read on this forum, somewhere, that there were two diffierent auto tensioners and that one of them had finer teeth and did not over tighten. I wish I knew more about this because mine is annoying.